Carrier and gripper for bag filing machines



Dec. 19, 1939. s, CHANDLER 2,184,178

CARRIER AND GRIPPER FOR BAG FILLING MACHINES I Filed May 25, 1937 2 Sheets-Sheet 1 IIIIIIIIH "P -u 1 43 L WII v INVENTOR. JuJT/A/ 5. (Jew/V2455,

1 j ATTORNZ 1939 A. s. CHANDLER CARRIER AND GRIPPER FOR BAG FILLING MACHINES Filed Ma 25, 1937 2 Sheets-Sheet 2 IN VEN TOR. (IVA/V0455,

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" ORNY Patented Dec. 19, 1939 UNITED STATE PATENT OFFICE CARRIER AND GRIPPER FOR BAG FILLING MACHINES Application May 25, 1937, Serial No. 144,728

3 Claims.

This invention relates to work holding devices suitable for use in various situations but particularly useful in flat bag filling machines of the kind illustrated in my copend'ing application Serial No. 108,487, for Bag filling machine. filed October 30, 1936, and is a continuation of that application as to Figures 6, 7, 8 and 9 herein.

It is an object to minimize the mechanism and material required to effect the gripping and supporting of a bag throughout a sequence of operations in the filling machine and to release such bag. At the same time more effective security of support and retention of the bagis attained, beginning immediately at the initial station, leaving no interval between the moment of release of the bag from the filling means at the loading station and its movement through subsequent bag-working mechanisms, when it is not held rier device.

It is a further purpose to enable the operation of a gripper on a conveyor with a minimum of structural elements located beside the path of the conveyor, whereby access to the parts of such machine for cleaning, adjustment and repair will be obstructed in a minimum degree, and whereby bag-working units may be located beside the conveyor without interference or crowding.

A further object is to present a novel and simple construction in the gripper device and its operating mechanism.

Another object is to accomplish better shaping of the packages produced in the machine.

Additional objects, advantages and features of invention reside in the construction, arrangement and combination of parts involved in the embodiment of the invention as will appear from the following description and accompanying drawings, wherein? Fig. 1 is a fragmentary section of a machine such as shown in my said prior application, showing my present carrier and gripper closing means;

Fig. 2 is a front elevation thereof;

Fig. 3 is a top view of the machine with all parts removed over the table 41, and showing my gripper closer operating means;

Fig. 4 is a fragmentary top view of the index table or conveyor showing grippers in open and closed positions;

Fig. 5 is an enlarged cross section of the gripper and closer;

Fig. 6 is a part of Fig. l, in my said prior application as the filling station;

Fig. 7 is a similar view at the delivery station;

securely in proper operative position on the car- Fig. 3 shows the gripper closed as in said application;

Fig. 9 is a plan similar to Fig. 3, showing the position of the rail 238;

Fig. 10 is a view similar to Fig. 5 showing a preferred form of gripper adapted to function in the same way as the one of Fig. 5;

Fig. 11 is a front elevation of the last named modification;

Fig. 12 is a view similar to Fig. 3, showing the use of a closing rail functioning like the rail 38, to close the grippers of Figs. 1 to 5 and 10 to 12, inclusive.

There is illustrated the knee bracket 43, main shaft 80, table 41 and hollow center post 8| of my prior application named above. The shaft 20 operates bag working units by radially extending operative connections as shown in my said prior application. A main cam I06 is shown, differing from that in said application only by having a boss cam on its lower face, as will be described.

The index frame revoluble on the post 8| may be rotated step by step by any suitable index mechanism, in synchrony with the cam I06, that is, one step for each rotation of the cam, and in my said application the index means is operated by an element of the cam I06 itself.

The hub In of the frame 85 is extended upward around the post 8! suitably, and has se- 7 cured thereon a spider H, the hub [2 of which is secured for vertical adjustment on the hub It] by means of a set screw l3. The spider includes arms M and a rim I5 rabetted on its upper and lower sides to receive base blocks l6 of carriers or grippers I! secured on the rim l5 at proper intervals. The. spider may be considered a part of the index frame, and may be termed broadly a conveyor.

The gripper base block is formed with a mounting flange I8 at the inner side adapted to set in either of the rabbets of the rim l5, and secured by means of screws engaged through the flange and in the rim. For longer bags the block is set on the under side of the rim. At its outer part the block is extended upwardly with a suitable width to form a back rest i9 for a filled bag, the horizontal bottom edge of which bag may set upon two rectilinear pins 20 set in the lower part of the block and inclined slightly upward toward their outer ends. The back rest may be of the same width as the maximum size of bag which is to be filled in the machine.

The lower part of the block It is formed with two cars or knuckles 2| inclined forwardly of the plane of the front face of the back rest l9 and transversely bored to mount a shaft 22 revolubly therein. The ears stop short of the ends of the rest Hi to afford a clearance for the mounting of two pincher arms 23 fixed on the shaft and extending upwardly so that their upper ends may swing inwardly against the rest (5 a short distance below the top of the rest. Rubber or other facings'23 are provided on the upper ends of the arms 23 to effectively prevent slipping of a bag clamped between the arms and the rest I 9. Between the ears 2! there is secured on the shaft 2| a cam block 25, having a V- shaped cam face thereon, the high part of which projects toward the rear under the base block 56. A flat face or relieved part 2E5 is formed on the base block offset back of the front face of the back rest so as to receive thereon the upper end of a leaf spring 21 held thereon by suitable screws. This spring is extended downwardly and rearwardly beneath the rim l5, and then re curved forwardly and upwardly and extended to form a flat end having wiping engagement against the cam and adapted to hold the cam yieldingly with either of its flat sides engaged. With one side of the cam engaged as in Figure 1, the arms 23 are held in forward or open position away from the back rest l9, and when they are moved inward a distance the high part of the cam passes dead center with respect to the wiper end of the spring while the arms are still spaced from the rest I9 and the spring then presses the cam to its limit of movement determined by engagement of the arms either with a bag on the pins 2!] or with the back rest l9.

One of the arms-the one on the left in the present instance, as viewed in Figure 2-is formed with a boss 28 at the lower part below the shaft 22, in which boss thereis set a tail pin or cooking pin 29. At a suitable point beside the path of the carriers there is fixed a cooking rail 38 or other device with an inclined portion 3! disposed so that by advance of the conveyor it will engage the lower part of the pin 29 when at or near the outer limit of its swinging movement, the portion 3| being from this point of initial engagement inclined inward in the direction of movement of the conveyor a distance such that under advance of the conveyor the pin 29 will be pressed inward until the high part of the cam block 25 has passed dead center of its engagement with the spring 21, a suitable distance which may correspond to full open position of the arms 23 if desired.

For closing the grippers there is provided a bracket 32 mounted on the front edge of the table 41 on which there is rockingly mounted a shaft 33 having an upwardly extended arm 3 fixed thereon from which a horizontal pin or arm 35 is extended to lie in front of the left hand arm 23 of the gripper device when the carrier is at the filling station of the machine, or other position where the grippers are to be closed. By rocking the shaft to swing the pin 35 against the arm 23, the arms 23 are moved toward engaged or gripping position where they will be held by reason of shifting of the cam on the spring 21.

The shaft has an outwardly extended arm to which there is connected a vertical link 3? extended downwardly through an opening in the table 47, where it is connected to the outer arm of a lever 38 pivoted on a bracket on the knee bracket 43 and which lever includes an inwardly projecting arm 39 having a wiper 49 plate 42 and the lever 38.

thereon close under the cam I06. The lower side of the cam I06 is planiform except for a cam boss 4| of short extent, engagement of which with the wiper will rock the shaft 33 sufiiciently to close the gripper immediately before the conveyor moves the carrier from the station, The link 3'! is engaged slidably through a seat plate 42 on the table 41, and a helical spring 43 engaged around the link is confined between the This serves to hold the grip closing device in initial or released position (when the gripper is open), yieldable to action of the cam 4|.

Various modifications of the device may be embodied without departing from the spirit of the invention, and in Figures 6 to 9, inclusive, carriers 95 are shown each consisting of a bracket casting 221 having a back flange 228 secured against the under side of the ring 93 by bolts 229, and having an upstanding front portion 230 on which a back plate 23! is secured, extending upwardly and inclined inwardly to the wall 9i mounted on arms 9!! of the index frame. Two rest or shelf pins 232 are each set removably in one of respective vertical series of holes in the bracket, projecting forwardly to receive the bottom edge of a bag and support the same as a shelf while it lies against the back plate. The pins are thereby adjustable to different heights on the carrier. The back plate has two integral wings 96 before referred to, turned forward from respective sides at the upper part, to steady and retain the bag until engaged by a gripper lever device on the carrier unit. At the lower side of the bracket, depending knuckle ears 233 are formed thereon between which is pivoted a gripper lever 234 having an upper grip arm carrying at each side soft rubber pincher knobs 235 adapted to press upon the lower part of a bag at each side, and a lower wiper arm on which there is mounted a wiper roller 236 on an axis nearly or quite radial to the pivot of the lever. Around the pintle of the lever there is engaged a torsion spring 211 having respective arms engaged with one ear 233 and the upper arm of the lever 234 whereby to press the knobs 235 yieldingly toward the plate 23!. A cam rail 238 (see Figs. 6, '7, and 9) is mounted by suitable upstanding brackets 239 on the table 41, immediately adjacent the index table, extending from the sealing station to the filling (or loading) station. It is concentric with the index table except at the ends, where it is curved outwardly as at 240, Fig. 9, and is so located as to engage and hold the roller 236 pressed inwardly to a sufficient distance to hold the lever 234 and its knobs in the desired open or released position. Adjustment of these carriers to accommodate bags more or less deep is effected by adjusting the ring 93 on the wall 9|, by a suitable means, not shown herein. Accommodation to different bag lengths may also be effected by adjusting the pins 232 up or down in the respective series of holes in the bracket.

The outturned ends of the rail 23B are so inclined that the engagement of the gripper with the bag 230 will not be abrupt nor tend to damage the paper or contents, nor produce objectionable permanent indentations in the paper of the bag, and the release movement is effected without undue shock or consumption of power.

The use of the plate or wall 9! of my prior application, on the index table or frame has been found unnecessary, but if necessary a supporting plate may be incorporated in any bag Working or other device at the station where such support is necessary, in various machines.

In the operation of the device of Figures 1 to 5, the carrier being at the loading station as shown in Figure 1, it will be in open position. A bag will be dropped on the pins 26, and the cam boss M will immediately after operate the lever 38 and cause the bar 35 to press the arms 2;; inward. As soon as such movement has progressed sufli ciently to move the high point of the cam 25 past dead center on the spring 21, the pressure of this spring thereon will tend to rotate the cam further and may effect the final movement of the gripper arms until the friction facings 2t engage the outer face of the bag near opposite edges, and press the bag against the rest IS. The index frame or table 85, as part of a conveyor device, will now move the carrier step-by-step or otherwise along the path determined for the loaded bag. Near the end of the path or course of the loaded bag on the conveyor, the rail 30 is located so that the inwardly inclined part 3| will engage and press the pin 29 inward, and so open the gripper, freeing the bag for removal or discharge by any approved means, of which several forms are well known. The final movement of the arms 23 in opening movement may be caused by the action of the spring on the cam the reverse of the closing action, so as to rotate the shaft 22 until checked by engagement of the spring against the lower flat side of the cam.

Adjustment of the carri rs to accommodate of various heights so that their tops may be worked by devices of fixed level as in my said prior application, is accomplished by loosening the set screw I3, and adjusting the hub l2 of the spider higher or lower on the hub IQ of the index frame and for bags of extreme height, in addition, the carrier units may be taken from the top side of the flange Q8 of the spider rim I5, and secured to the lower side thereof, as before indicated.

The construction of Figures 6 to 9 functions by the action of the spring 211 keeping the gripping device closed at all times except when it held in open position by the rail 238, which is the case from the time the carrier reaches the discharge position adjacent a discharge gripping and sealing device talk-SIB, until the beginning of their departure from the loading station in the direction indicated by the arrow in Figure 9. The loading station may include a bag presenting means and loading means formally represented at l3li-328. Numeral 259 indicates one of a series of top bag top working devices arranged along the path of the bags on the conveyor as in my said prior application.

The assembly of the shaft 22, and gripper arms may be termed a yoke.

The rubber facings 2t on the arms 23 may be of such size and material that they will yield sufficiently to compensate for moderate differences in thickness of the package at opposite sides as may be appreciated.

In Figures H3 and ii there is shown a further modification of the invention which may be preferred. In this instance the arms 23 are modified and the cam omitted. In place of the arms spring fingers 23' formed of thin band spring material are secured to the front sides of hubs 43 fixed on the shaft 22 in the same positions as the bases of the arms 23 before described. The outer end portions of the spring fingers are bent slightly outward and may have slipped thereover rubber sleeves M, as facings. The hubs are suitafford a good flat face to receive the base of the spring 23, and one may have the cocking pin 29 set in its lower side, as before described. A short necked lateral stud 45 is set in the thickened side of the back rest l9 near the top of the latter, and set back from the front face of the rest, while a similar lateral stud 46 is set in the outer side of one of the hubs 43 in such position that when the fingers 23 are in open position the stud 5 will lie on a line passing inwardly of the shaft 22 to the upper stud 45; and when the fingers 23 are in engaged position the stud 46 will lie on a line passing outwardly of the shaft 22 to the upper stud. A contractile helical spring $8 is connected between the two studs under sufficlent tension alternatively to hold the fingers properly engaged with a filled bag yieldable to the cooking rail 36, or to hold them in open position yieldable to the arm 35 of the closing device. The spring i8 is of sufiicient strength to cause slight fiexure of the fingers 23' when the latter engage a filled bag or the back rest, so that the finger engaging a thicker portion of a bag may yield and permit the other finger 23' to also engage the bag, increasing the security with which the bag is held during the subsequent station bag-working treatments involved in such a machine as referred to. To check the fingers at proper open position, a lug or stop pin 49 is formed at a suitable location or engaged in one of the hubs 63 at the rear side and arranged to strike the lower face of the base block over the hub t3 when the fingers are spaced sufficiently from the back rest.

A retaining washer 59 may be secured to the shaft 22 between the ears 2 l, or other means provided, to secure the shaft 22 between the ears 2i, or other means provided, to secure the shaft against longitudinal movement on the base block.

It should be understood that if desired, other means than the arm 35 and its operating means may be utilized to operate the gripper devices, as opener 39' (Fig. 12) similar to the rail 36, but oppositely inclined from within the path of the conveyor, so as to engage the arms 25 at the inner sides and force themv outwardly.

I claim:

1. In a machine of the character described, a conveyor movable in a fixed path and having thereon bottom rest supports for bag bottoms, means to deliver fiat open-end bags upon said supports in erect position in a plane substantially coincident with the path of the conveyor, and means spaced further beside the path of the conveyor to work the tops of bags for sealing and to discharge bags, a back rest for the bags on the bottom rest, and a plurality of bag grippers each consisting of a bag-pressing yoke pivoted on the conveyor below the bottom rest and spring-loaded and extended and movable upwardly and inwardly toward the lower end portion of a bag on bottom rest and constructed and arranged to hold the bag against said back rest, and means beside the path of the conveyor at the discharge station and the loading station to engage and move the grippers to open position, and to move the grippers to engaged position at the loading station cooperative with the discharge and loading means.

2. In a machine of the character described, a conveyor having a series of base supports thereon each having a laterally presented bag supporting surface, means to present bags thereon irom above, each support having a pivot shaft at the lower part alined with the direction of movement of the conveyor, a cam on the shaft having a high part and two flats extending in opposite directions therefrom, a spring loaded wiper on the mounting having a fiat face arranged to bear on the flats alternately, and to yield to the high part on rotation of the cam, whereby the cam will be held yieldingly in opposite position alternately, a yoke fixed with relation to the cam having a bag gripping arm projected upwardly and arranged to be at its inner limit of movement over the the support adjacent said supporting surface when the upper fiat of the cam is engaged under the wiper, and to lie at open position upwardly extended and outwardly inclined when the opposite flat of the cam is so engaged, and means to move the yoke to gripping position and to move it to open position at respective parts of the path of the conveyor.

3. The structure of claim 2 in which there is provided a downwardly extending arm fixed with respect to: the yoke, and said means to move the yoke to open position consists of a rail inclined across the path of the last named arm in its movement with the conveyor and the means to move the yoke to gripping position consists of means to engage the yoke and move the same to closed position, said yoke being constructed as described in this claim.

AUSTIN S. CHANDLER. 

